Telecommunication systems for wireless communication (having in each case at least one base station and at least one battery-operated mobile part) include, e.g., cordless telephones which have a cordless base station with an integrated or a separate battery charging device and at least one cordless mobile part. With the above telecommunication systems it is possible over short distances and in a mobile manner via the fixed network, e.g., the ISDN or PSTN, to telephone or make local and long-distance calls, i.e., voice data, to transmit or exchange packet-based data, e.g., SMS messages.
Moreover, within the foreseeable future there will also be cordless telecommunication systems which are suitable for the transmission of voice and packets over the Internet. Consequently, and despite the worldwide dominance of mobile radio devices (GSM handsets or soon UMTS handsets), there will also be a worldwide market for such cordless telecommunication systems in the future. The market possibly growing even bigger, however, particularly in view of the WLAN and IEEE 802.11 application scenarios that are currently under discussion. The DECT protocol is currently the most widespread protocol, in Europe at least, upon which such cordless telephones are based.
FIG. 1 illustrates a known cordless telephone SLT. Specifically, FIG. 1 illustrates a Siemens Gigaset 4175isdn that includes an ISDN-compatible cordless base station BS of the type Gigaset 4175isdn, a cordless handset HA of the type Gigaset 4000C developed to include convenient menu prompts (menu protocol), and a separate battery charging device ALE for charging the batteries in the cordless handset HA, which works or functions in accordance with the DECT protocol. The cordless handset HA features a display AE and a keypad TA on which are located, for example, an operating element that is developed as a start call key for starting a call GST and an operating element that is developed as an end call key for ending a call GET. The cordless base station BS has an operating element for establishing logon readiness AT, the operating element preferably being developed as an illuminated logon key, which flashes when it is activated.
In order to allow the use of such cordless telecommunication systems for wireless mobile telecommunication, the cordless telecommunication systems include two devices (cordless base station and cordless handset), which are “married” to each other. The marriage of the two devices occurs when the cordless handset HA is registered or logged on at the cordless base station BS. EP 0 667 078 B1 provides a detailed description of the fundamental way in which such a logon procedure takes place; in particular for DECT-specific cordless telecommunication systems.
Both during such a logon procedure and in advance of the logon procedure, i.e., when establishing logon readiness, all cordless telecommunication systems formerly required the user to act and, for example, switch both the base station and the handset to logon-ready in the defined sequence (i.e., by pressing the logon key AT or the start call key GST or the end call key GET, enter a personal identification code or so-called “PIN” (Personal Identification Number), and select an INTERNAL number for the handset). The logon key AT and the start call key GST or end call key GET are, therefore, means for establishing logon readiness with regard to the cordless base station BS and the cordless handset HA. These measures which had to be performed by the user were not exactly user-friendly, and the logon procedure was, therefore, performed in advance by manufacturers of such cordless telecommunication systems as part of the manufacturing process. Although this did improve the user-friendliness for the purchaser of such cordless telecommunication systems, it also increased the manufacturing costs at the same time. In order to avoid the necessity of the latter (increasing the manufacturing costs) without neglecting the former (improving the user-friendliness), WO03/003702 A1 provides for logging on battery-operated mobile parts at base stations.
This method includes the automatic establishment of the logon readiness between the mobile part which must be logged on and the base station, without the user of the telecommunication system having to carry out the measures that are described above. This is achieved by establishing the logon readiness for logging on the battery-operated mobile part at the base station including a battery charging device via charging contacts of the mobile part and of the base station. The logon procedure then taking place as before via the air interface of the telecommunication system.
The means for establishing logon readiness (with reference to the cordless base station including battery charging device and the cordless handset) include the battery charging device and the charging contacts. With the cordless telephone which is illustrated in FIG. 1 as its point of departure, a further evolution step in the development of cordless telephones includes miniaturizing the cordless handset HA, e.g., in the direction of cordless earphones and at the same time progressively introducing a voice-controlled user interface of the cordless handset HA. The objective is to move away from the current cordless handsets including user operation via keys and display, and move to more compact and smaller cordless handsets, e.g. “earplugs” which are designed as cordless earphones, in which the user operation is entirely voice-controlled. The “earplug” is functionally comparable with current cordless handsets, but without a display and keypad.
As a vision which has FIG. 1 as its point of departure, FIG. 2 illustrates the cordless telephone SLT of the type Gigaset 4175isdn being extended to include a cordless earphone OA. In comparison with the cordless handset HA which has been used until the present time, the cordless earphone OA which is designed as an “earplug” has only a single key, e.g., the start call key or “Push2Talk” key GST. Although the cordless handset HA and the cordless earphone OA clearly differ in terms of the user interface, they are both cordless mobile parts MT which must be registered at the cordless base station BS in the context of a logon procedure for the purpose of operating with the base station.
In the case of conventional user operation, the logon of a cordless mobile part at a cordless base station (registration) takes place in such a way that the cordless mobile part and the cordless base station are switched into a special logon mode and—as mentioned above—the “PIN” (Personal Identification Number) must be entered for user authentication at the cordless mobile part, so that it can be accepted by the cordless base station accordingly in the context of the logon procedure. This type of logon procedure which is based on conventional user operation requires that the cordless mobile part have a keypad and a display.
The omission of display and keypad in cordless earphones requires alternative forms of user operation when logging on a cordless mobile part at a cordless base station in the context of a logon procedure. A hardware-triggered automated logon procedure is, therefore, used in the known cordless telephones of Siemens such as the Gigaset 100 and Gigaset 200, for example. A further possibility for user operation during the logon is to use an existing voice-recognition infrastructure for voice-controlled user operation during the logon. In this case, the infrastructure is present in the telecommunication system (e.g., base station or mobile part) on the basis of the voice-controlled user interface which is provided in any case.
Cordless telephones which have an infrastructure for voice recognition are already available on the market. Examples include the Siemens cordless telephones of the type Gigaset (Series 4xxx), in which the base stations are equipped with voice controls. In accordance with WO 01/67435, these voice controls make it possible by speaking the name to dial the corresponding telephone number from a phone book which contains a maximum of 20 entries. This is a speaker-dependent method, in which, e.g., four different speakers can train a corresponding voice recognition facility using their specific voices in internal databases (Example: There are two users. Each user gives a voice sample for each entry. Therefore a maximum of 10 entries are possible.). This feature is comparable with the voice control which is integrated in mobile telephones.
All in all, therefore, the current voice controls are rudimentary in comparison with the possibilities which are created in accordance with WO 01/15141 by the new speaker-independent methods, the possibilities being based, e.g., on a “Hidden Markov Model.” As a result of such speaker-independent methods, it is also possible for the first time to implement voice-controlled user operation when logging on a mobile part at a base station in the context of a logon procedure.